I got some Pi Hat templates recently and was playing a game of "let's see if I can print a 0.5mm FPC connector footprint". I'm pretty hopeful about the Pi template as it solves a lot of the issues I had the last time I tried doing a hat with the V One (mainly the stability of the connector, and having a lot of vias). For me, my OtherMill makes quick work of the holes and cutting the outline perfectly, but having real plated-through holes with breakout pads on both side of the board is really handy.
The FPC connector required careful calibration of the Z height and flow rate, and the resulting footprint looked promising, at least unbaked. But I destroyed a nozzle during the experiment, and I think I know why.
When probing for Z height, the V One doesn't seem to account for the notion that there may be copper pads there already, which are ever so slightly raised above the substrate. So with a Z height of 0.08, I'm pretty sure the nozzle got bent when it tried to lay down ink over one or more of the existing pads on the template. That in turn caused a slit at the bottom of the taper, which slowly oozed ink during the rest of the print.
At first I thought that perhaps next time I would deselect the template's pads, print, then recalibrate the Z height to be higher. But that only goes so far. Not only does the toolpath essentially print a pad on top of pad, but the traces extend into the pad as well. So I'd run the risk of a nozzle collision on one of the traces that terminates on a template's pad.
Any creative ideas on this? I'm not familiar enough with Gerber and Eagle's CAM processing to know how you might leave hints for the V One to watch for the speed bumps on a template. Or if such a thing is even possible.